Cryogranulation equipment is commercially available for the manufacture of frozen product pellets in the food industry. In particular, cryogranulation systems used in the food industry are suitable for preparing frozen foods, such as ice cream. U.S. Pat. Nos. 6,216,470; 7,062,924, and 7,475,554, for example, disclose systems used for cryogranulation, which disclosures are incorporated herein by reference.
Cryogranulation systems may include a tray or channel carrying a flow of a cryogenic liquid, such as liquid nitrogen. A material to be cryogranulated is introduced into the flow of liquid nitrogen from a dispenser positioned above the tray. The material is frozen by the liquid nitrogen into pellets or granules. At the end of the tray, the liquid nitrogen and the frozen pellets are separated, typically using a screen. The liquid nitrogen is returned to the upper end of the tray to form a closed loop circulation of liquid nitrogen. The frozen pellets may be used as is or subjected to further processing. The terms “cryogranulating” and “cryopelletizing” are used more or less interchangeably.
Some processes, such as manufacturing of pharmaceutical formulations, require precise control and repeatable results. Prior art cryogranulation systems have not heretofore been suitable for manufacturing of pharmaceutical formulations. Accordingly, there is a need for improvements in the design and manufacture of cryogranulation systems and methods for use in manufacturing of pharmaceutical formulations.